Noise Induced Hearing Loss: Re-emergence of an old workplace problem

Transcription

1 Noise Induced Hearing Loss: Re-emergence of an old workplace problem Professor Malcolm Sim Centre for Occupational & Environmental Health, Monash University, Victoria, Australia

2 Noise induced hearing loss In 2005 financial cost of hearing loss was estimated: $11.75 Billion or 1.4% of GDP (Access Economics) 37.1% of Hearing loss in adults is NIHL (Wilson et al, 1998) High proportion of NIHL is due to the workplace Workplace noise has been around since ancient times Strong perception that noise exposure is under control Well established hierarchy of controls Despite this, concerns about increase in burden of NIHL

3 Occupational NIHL in Victoria Aim to analyse time trends and the demographic and occupational characteristics of workers claiming for NIHL related Impairment Benefits (IB) and hearing aids (HA) through WorkSafe Victoria Funded through the Institute for Safety, Compensation and Recovery Research (ISCRR) a joint initiative of Worksafe Victoria, the Transport Accident Commission and Monash University compensation database

4 Methods Data based on computerized claims (excludes Commonwealth employees, sole traders and self Insurers, about 8%) Covered period for all claims 12 Nov 1997 (when NIHL claim threshold increased from 7% to 10%) to 30 June 2009 Claims coded by affliction nature code, deafness code 250 or 771, n=5183 claims Excluded 772 due to audio shock, 206 not related to hearing, 12 disease of mastoid and 6 due to trauma Payroll used to estimate Workplace size: >$1m, $1m to $20 m, >$20m (not number of employees) Crude industry/occupation categories

5 Impairment benefits

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7 Costs

8 Industry analysis

9 Workplace size

10 Industry/workplace size Incidence of IB claims by workplace size - Manufacturing: similar incidence rates at the beginning of the period, higher upward trend in small and medium workplaces from onward - Construction: increase in small workplaces, steady rates in medium workplaces, upward trend in large workplaces

11 Thorne PR et al. Epidemiology of noise-induced hearing loss in New Zealand. N Z Med J Aug 22;121(1280):33-44.

12 Conclusion: The substantial and increasing societal costs despite decades of NIHL control legislation suggests that current strategies addressing this problem are not effective, inadequately implemented, or both. Thorne et al. 2008

13 Workers in Mining, Construction, and specific Manufacturing industries appear to have a much higher prevalence of hearing loss. Although noise exposure in these industries has been regulated for decades by OSHA and MSHA, these results suggest that the current regulations and their enforcement need to be revisited.

14 Other recent publications highlighting NIHL Pawlaczyk-Luszczynska M, Dudarewicz A, Zaborowski K, Zamojska M, Sliwinska-Kowalska M. Noise induced hearing loss: research in Central, Eastern and South-Eastern Europe and Newly Independent States. Noise Health Jan-Feb;15(62): Fuente A, Hickson L. Noise-induced hearing loss in Asia. Int J Audiol Mar; 50 Suppl 1:S3-10. European Commission report on the current situation in relation to occupational diseases' systems in EU Member States and EFTA/EEA countries, 2013 NIHL a common priority condition

15 Should there be a reduction in the workplace noise guideline values?

16 Review updated in 2012

17 Cochrane review Recent Cochrane systematic review showed a lack of good evidence for effectiveness of interventions to prevent occupational NIHL (Verbeek et al, 2009 and 2012) Low quality evidence that implementation of stricter legislation can reduce noise levels in workplaces. Effectiveness of hearing protection devices depends on training and their proper use. very low quality evidence that the better use of hearing protection devices as part of HLPPs reduces the risk of hearing loss. Better implementation and reinforcement of HLPPs is needed. Better evaluations of technical interventions and long-term effects needed.

18 Barriers to effective noise control programs Focus groups workers/employers: an over-reliance on personal hearing protectors infrequent and improper use of personal hearing protectors, lack of prominence of noise as a serious work health and safety issue insufficient knowledge of the effects of loud noise on hearing and quality of life belief that noise control costs too much belief that hearing loss is inevitable small or medium-sized businesses

19 Key points Despite increase in threshold for accepting NIHL claims, numbers and rates are increasing in Australia (particularly over past 5 years) Mirrors the situation in several other countries Increased awareness to claim? is so, suggests previous underreporting, as with most occ diseases Results suggest noise management programs over past 30 years sub-optimal Cochrane review shows that increasing regulation unlikely to be effective Burn out and complacency in workplaces Need for greater enforcement in noise control and efforts in hearing protection programs, not just relying on hearing protectors